Wire line jar tool



Sept. l1, 195,6 w. E. BARNES WIRE LINE JAR TooL Filed may 1s, 1955 INVENTOR.

WILLIAM E. BARNES United States Patent v'O WIRE LINE JAR Toor.

William E. Barnes, Beaumont, Tex., assignor to Sun Oil Company, Philadelphia, Pa., a corporation of New Jersey Application May 18, 1955, Serial No. 509,281

' s claims. (c1. zss-z1) This invention relates to a well tool and particularly to that class of well tools run on a cable in conjunction with other well tools and appliances, and specically used to loosen these other tools from binding in the tubing by a jarringaction.

An object of this invention is to provide a jarring tool that s operable to effect a controlled jarring action.

Another object is to provide a novel cable tool in which a predetermined jarring force may be established and is unfailingly operative.

Still another object is to provide a tool of the character stated capable of repeated action, in which the force effected on returning it to the operating position for repeated jarring blows is minimized.

.These and other objects are attained by a jarring tool of the usual hammer and anvil typeincorporating a magnetic means as the restraining element. of selected field force forms the opposed fixed and movable sections of the jar tool. Uponfapplication of an upward lifting force on the suspending cable, suflicient to overcome the magnetic attraction holding the magnetic means together, the restraining force is overcome, and the hammer portion sharply released to strike on the anvil. Controlled lowering of the cable suspended hammer allows the magnetic means to reengage without striking a downward drive to repeat the operation of other blows all tending to release the strike condition.

A more detailed description of the invention emphasizing the above objects, and others, together with a complete disclosure of the structure and function, follows as a description of the accompanying drawing, in which:

Figure l is an axial section through the jar incorporated in a drill string as it passes downwardly in Well tubing;

Figure 2 is an axial section showing the jar in operation; and

Figure 3 is a sectional view of the magnetic means employed, taken on line 3-3 of Figure 1.

The device of this application is illustrated in one form as it would appear as part of a tool string being lowered into tubing which is suspended in casing 12 in a well bore hole. A wire line 14, normally of small diameter to pass through a packing gland for conservation purposes, is the means of connecting tools or other exploratory elements diagrammatically shown as number 16 with the surface.

Between the lower end of the wire line 14 and the tool 16, the jar mechanism of this application, generally denoted by the inclusive number 18, is positioned. A tubular body portion 20 is fashioned at the lower end 22 to support a tool or other device 16. As shown this can be in the form of a solid section reduced in diameter to meet the connected tool, being drilled and tapped as at 24 for such tool engagement. The lower portion of the tube 20 is thus shown to be of solid structure in this embodiment. However, it will be evident that it can be an open cage-like structure for easy passage of liquids and gases through the tubular body portion 20.

This section of the body portion, in addition to mount- Magnetic means 2 ing the suspended tool 16, is designed to hold a permanent magnet 26 forming a restraining means for u-se in the jarring operation. Set screws 28 hold this magnet in operating position in the bottom of the body portion 20.4

Magnet 26 is of the well-known concentric pole construction which lends itself particularly well to the tool jar of this application. Other forms of permanent magnets can be used if desired without changing either the general construction or operating principles disclosed here; This form of magnet used in cooperation with a like magnet with reversed poles, conserves the magnetic field for maximum operating efficiency as will be fully understood on reading the following additional descriptive material.

Slidably movable in the tubular body portion 20,V hammer means 30 extends into engagement with the wire line 14. The second permanent magnet 32 of reversed pole pieces, as indicated in Figure 2, forming a complementary element in the restraining means, is fastened to the hammer means 30. One form of connection between the magnet 32 and the hammer 30 is shown here as a threaded stud 34 adapted to engage a like threaded hole in the magnet. The portion 36 of the hammer 30 is enlarged to assist in keeping the hammer aligned in the tubular body 20 as it Slidably moves therein, and also presents the hammer head 38 which strikes against the anvil 40. A reduced portion or handle 37 of the hammer connects with the head 38 and extends upwardly through the annu; larly formed anvil 40 into operating contact with the wire line 14. By threadedly engaging the annular anvil 40 as at 42 with tubular body 20, the impact of the hammer head 38 is transmitted through the jar tool to the suspended tool 16, as will be disclosed in the description of operation. The anvil is ape'r'tured as at 44-44 to receive a spanner wrench for keeping the anvil 40 securely in place.

Above the anvil, the extending portion of the hammer means 30 is shown enlarged at the wire line anchorage portion 46 and headed at 48 where wire line 14 is received. One form of securing the wire line 14 is shown inside anchorage portion 46 to include a ball end 4S fastened to the end of wire line 14 which bears against washer 43 and compression spring 41. By such an arrangement the jar 18 is resiliently supported within the tubing 10. This structure diagrammatically illustrates an engaging means for the wire line and hammer which can be easily changed with any desired mechanical adaptation. Additionally the enlarged portion 46 adds weight to the hammer 30 increasing the inertia of this slidable element assisting in the jarring action.

Figure 2, compared with Figure 1, forms the basis for describing the operation of the device. Toindicate a condition of improper operation such as sticking of the tool 16 preventing wire line movement to continue the operation, the jar and tool are shown askew in the tubing 19. In order to free the tool, wire line 14 is tightened until the magnetic lield between the two magnets 26 and 32 is initially overcome, separating them.

The well known laws of the strength of attracted magnetic telds enables the calculation of the force necessary to initially separate these magnets. Once separated, the magnetic effect decreases directly n proportion to the square of the distance between the magnets. As thev 'Having delivered the blow, vwire line 14 is slackened and the hammermeans 30 with .attached `magnet 32 is permitted to slide downwardly in the tubular body 20, the stuck condition assumed to be unrelieved at this moment. As'mnguet ,32y slides downwardly to join .fits :magnetic 'intuence-iwith thezeld :df magnet 26, fthe V:magnetic k'attractionrbetweenthezmagnets becomes stronger .andr stronger. Thisattraction increases in reverse of the separating rTinuence 'discussed above, culminatingin :electrical "engagement `withfull forceon-'contact Repeatedililowsand .returns .to the restrained-position', :makin g .theseblows 'effective, -willzreleasethe tboundstool. v

n-rorn tthe a'bove 'description vof lfthe :device audits-oper- Aation, -it will `:be 'evident :that fthe jarring *tool fof zinventiomhasmianyfadvantages .over Ythose presentlyxlcnown. Flheemagnets, creating fthe 'zrestraint'which makes the :final jarring blow fso effective, :require no positive return `,to the :starting position for .latching collapsing, or :other action. *Contact'will 17e-.made .between thel magnets and theftrestrainingefor', reestablished fon 'the lightest touching, and assisted, magnetically, to assume :the beginning of ythe operation.

fFurther, the strength vof the :restraining 'force Scan be varied within vdesired `ranges .by "selection of vdifferent strength magnets. lOnce 'the wire line 14 vvis selected as proper for operating this .jarring tool, the iline will `not beparted because of a 4latchnot workin'g'or some other obstruction rto a mechanical Yreleasing mechanism.

Modificationsof the vabove disclosed preferred embodiment-of this'device will be immediately evident totthose versed in the art. 'In addition to changing v'the shapefof the magnets previously mentioned, changes, suchiias ornitting-one magnet as a means for `reducing the .restraining force, will be evident. Alterationsof `this'typehave been considered :by the applicant and are consideradas :being within 4the/scope of this disclosure.

Ingeneral `it lwill be evident, asindicated above, that thefpresentdevice is vcapable of many alterations inishape, number and type of elements, as well as miscellaneous 4 elements being added or omitted to facilitate operation, without vadding .to .unchanging .the .spinit `.of .the invention disclosed here. It is the intention of the inventor, therefore, to be limited only by the scope of the appended claims.

What is claimed is:

1. A wire line tool jar comprising an elongated tubular body, coupling means on thelower end of said tubular body attachable to a tool, an elongate'hammer means slidably operable in said .tubular body, wire linefastening means-on the upper end of said-elongateharnmer means and a head on the lower end, an anvil closing the upper end of the tubular body about the hammer means in position to fbe'str-uck'by the hammerhead, opposedfmagnets separately xed in the tubular body and on the hammer head respectively magnetically restraining the relative sliding movement of the hammer and the tubular body.

2. A wire line tool jar comprising elongate hammer means having 4a head :on .'the lower `end :andi-adapted to fasten :to 'a wire line ton .the other end, a'rtubu'lar .body positioned vEin relative 'sliding cooperation with 1sai'd iham mer, tool mounting .means .on the bottom of :the 'tubular body, an annular anvil closing the top of thetubularbody about 'the elongated hammer means between the upper and lower en'dsyand .magnetic means inthe ltubularfbody cooperatively restraining `.the relative sliding motionioffthe hammer :and tubular :body.

3. The jar of claim 2 further Iclraracterizedby -fsaid magnetic'emeans cooperatively'restraining 'the' relative-sliding .motion of the hammer and tubular body y:including opposed "permanent magnets of different .polarity vfseparately fixed to said hammer-and'tubular'body-respectively.

Referencesl Cited inthe file of 'this `patent UNITED STATES PATENTS 

